Thin films of hydrogenated amorphous silicon (a-Si: H) fabricated by plasma enhanced chemical vapor deposition (PECVD) are valuable for functional materials used in an electronic device such as solar cells. We have been applying molcular dynamics method with empirical (Tersoff potential) to analyze a-Si: H thin-film growth processes. As a first step toward film growth simulations, we confirmed that the potential is avalilable for molecular dynamics simulation of amorphous silicon (a-Si) formation in our previous work. Next, molecular dynamics simulation of a-Si: H formation with rapid quenching has been performed by defining new Tersoff-type interatomic potential between Si and H in this study. Visualization of the a-Si: H sample by computer graphics made it possible to see that there are some voids in the sample and that there are two kinds of hydrogen in the sample, (1) one hydrogen gather closely together and (2) the others lie scattered, which was predicted in IR absorption experimental results. As a result of the study of silicon hydrogen bonding form variety, it was observed that the number of SiH bonds decreases when total bonding hydrogen exceed about 17%, while that of SiH₂ Plus SiH₃ increases drastically, which is consistent with the obtained results by IR absorption or ¹HNMR experiment of other groups.